Introduction
Styrene is a monomer that is used to produce a wide variety of plastics. During storage of styrene and manufacture of these plastics, emissions of styrene can occur causing concerns of exposure for workers and release to the environment.
Case study: Reduction of styrene emissions during filling of storage tank
Styrene can be transported to polystyrene production plant in large chemical (inland) barges. Unloading of the styrene from these ships into the styrene storage tanks is done via the pipelines using the ships pumps at flow rates of typical 200 to 300m3/h. During this operation a gas stream containing high styrene concentrations is emitted from the storage tank. In order to avoid styrene emissions to the atmosphere companies can install an activated carbon abatement system to reduce these styrene emissions. Jacobi Carbons was contacted recently for an activated carbon abatement system for a plant with following average operating conditions:
Styrene storage tanks: 500 to 1,000m³
Ship pump flow rate: +/-500m³/h
Pumping time: 6 h per ship
Annual styrene consumption: 150,000MT/year
Styrene concentration: 17 g/m3
Styrene quantity 9kg/h
Annual pumping time 330 hpa
The local emission limits were 0,5kg/h hence the customer had to install a styrene abatement system
Our solution
The low explosion level (LEL) of styrene is 34g/m³. Therefor it was decided together with the customer to dilute the stream to be below 75% of the LEL and to reduce the heat of adsorption of the styrene abatement system. It was also decided to limit the styrene loading on the carbon to have a non-hazardous waste according to the local transport legislation. Following abatement system was successfully implemented:
Filter: Two EcoFlow™ C1 activated carbon filters in series and one in stand by
Activated carbon type: EcoSorb™ GXB 4 mm
CO detection
Intertisation with Nitrogen
Reduction of styrene emissions > 99,99 %
The end-user was very pleased with the result of the with the selected abatement system and the authorities could not detect any Styrene after the second activated carbon filter EcoFlow™ C1.
Don’t hesitate to contact us on styrene emission control solutions. Jacobi carbon’s activated carbon specialist are available to help you select the appropriate VOC abatement system.